Air conditioning system



June 2,11942. l L B. MILLER 42,284,914

. AIR CONDITIONING SYSTEM Filed July 16.11957 `2 sheets-sheet 1 ggg y 'feoli-Miller T0 HQUSE LBNES" June 2, 1942. 1 B. MILLER 2,284,914'

' AIR CONDITIONING SYSTEM 0 Filedv July 1e, 1937 2 sheets-sngg 2 Enom oUTsInE A' Patented, June z, `1942 UNITED STATES PATENT OFFICE AIRCONDITIONING SYSTEM V'Leo Miller, liartsdale.' N. Y., asslgnor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation o! Delaware .Application July 16, 1937,`SerialNo.`154,023 I (Criss-4) A 1s calms.

This invention relatesv to air conditioning systems and is more particularly concerned with air conditioning systems4 for summer cooling of the type utilizing a compression refrigeration system wherein-the compressor is'driven by means of an internal combustion engine.

One object of my invention is to provide a. dependable control arrangement for systems of this type, such control arrangement being low in iirst cost and acting automatically to start the engine when conditioning is required and to stop the engine when there is no demand for conditioning, the control system acting also to modulate the engine speed when in operation in accordance with variations in the demand for air conditionmg.

Another object of my invention is the provision `of an automatic control system of the type above mentioned wherein, the various controllersare pneumatically .actuated and wherein the actuating fluid for such controllers is provided by the prime moverwhich drives the compressor.`

A still further object vof my invention is toprovide improved air conditioning arrangements wherein a dehumidiiier of the type employing hygroscopic material is lemployed for removing moisture from the air, and whereincooling is done byjan internal combustion engine driven compressor, the heat ejected by the internal combustion engine being utilized for reactivating the hygroscopic material. l

Amore specific object of my invention isto cooling' arrangementwherein the air is rst dehumidiiied and heated `by passage .through an a novel control meansfor a. Vdehumidifying andabsorption or adsorption type of dehumidifier and is then cooled, the cooling `means being controlled v -in accordance with the` temperature of the air tion.

leaving the dehumidifier to thereby vary the operation of the cooling means in av manner vto carry both the latent heat and sensible heat loads on the system.

Other objects of my invention' will appear from the following'description and from the appended v claims.

For a full disclosure of my invention, reference is made to the following detailed description and `to the accompanying drawings, in which space At its other end the conditioning chamber l is connected tothe space 4 by a vreturn duct 5. 'I'he conditioning chamber I is also provided with a suitable fresh air -inlet duct 6, this duct having the usual damper means (not shown) for controlling the ow of fresh air into the condi- A ytioning'chamber. Located within the conditionprovide a highly economical air conditioning system of the type just mentioned. In accordance with my invention, I provide for passing recirculated air through the dehumidifying unit and adding tothe recirculated air just enough fresh air to secure proper ventilation. By utilizing substantially all recirculated air, the amount of dehumdif'lcation required for maintaining proper humidity conditions within the conditioned space isheld at a minimum. By this arrangement, the heat ejected from the engine is usually suillcient for reactivation of the'dehumidifying substance,

and hence the necessity of utilizingheat from an outside source for reactivation of the dehumidi-y fying substance eliminated. For extremely heavy dehumidifying load conditions, the waste heat from the engine willsometimes be insufcient for reactivating the .dehumidieri In or- -der t'o secure proper operation'of thesystem for taking care of such situations, I provide means for utilizing an outside source of heat for supplementing the wasteheat fromv the engine, and provide automatic control means for placing the auxiliary heating means in operation when the waste heat from the'engineis insumcient forreactivating thedehumidier. This featureform another object ,of my invention.

Afurther object .of my invention is to provide ing chamber is an adsorption Atype of drying means, and is herein illustrated as comprising a spray pipe I which sprays a suitable hygroscopic liquid, such as a lithium chloride solution, over the air being conditioned. The sprayed liquid is collected in a sump 8 forming part of the conditioning chamber. Reference character 9 indicates suitable separator plates for removing any liquid from -the sprayed air, this removed liquid flowing .down suchplates into the sump A8. In the condi# ticning chamber I, downstream of the dehumidi- I0 wherein it is cooled fying arrangement just described, is a cooling coil I0 for cooling the air beforeit is passed to the conditioned space. With the arrangement so fardescribed, it will be apparent that a mixture of fresh and return air is first passed through. the dehumidifying spray, then through the separatorgplates 9, and then over the cooling coil before being passed to the space 4.

The cooling coil 'IllA is herein shown as for-mqv ing part of a compressionv refrigeration system,

vthis system including also a compressor II, a

condenser I2 and an -Aexpansion valve I4, the discharge of the compressor I I being connected to the refrigerant inlet of the condenser I2 byva pipe l5, and the refrigerant outlet of -the condenser I2 being connected to the expansion valve Ahelfe.

u by apipe lo. 'me moet of uw cooling con -'Il is connected by a suction line I'I to the compressor II. The operation of compression refrigeration systems of this type is well known in the art, and therefore no detailed description is given However, it may be stated that operation of the compressor causes chilling of the cooling coil il and the temperature of the cooling coil Il will vary with the speed of the compressor and also with the temperature. of the air being in contact with said coil.

, Reference character 2l indicates generally an internal combustion engine, this engine having the usual exhaust manifold 2|, intake manifold 22, 'generator 23. ily-wheel'24 and starting motor 25. 'I'he ily-wheel 24 is connected to a drive shaft 26, this. drive shaft having mounted thereon a pulley 21 cooperating with belts 2B which run over a pulley 29 attached to the compressor crank shaft. Attached also to the drive shaft 26 is a pulley 3l, this pulley cooperating with belts 3l whichrun over a pulley 32 attached to the fan shaft. In'this manner the engine 2li drives the compressor ilA and also drives the fan 2. 'Ihe drive shaft 26 also drives a generator 33 bymeans of pulleys 34 and 35 which cooperate with belts 36. The generator 33 is adapted tosupply electricity for domestic use and for this purpose is preferably of; the third brush type having a storage-battery floating across the generator terminals. It will be understood that a suitable cutout may be provided for preventing discharge of the storagebattery through the generator when said generator is; not running. The drive shaft 2| is also arranged to drive a circulating pump` 38 by means of pulleys 3! and 4l which cooperate with belts 4l.

In accordance with my invention, the engine is automatically started and stopped in accordance with the air conditioning load.- When the engine is started. it is necessary to disconnectit from its load and for this purpose an automatic -clutching device is provided. The ily-wheel 24 f contains a suitable clutching mechanism, this mechanism bein'gactuated by means of a clutch collar 42. The clutch collar 42 is actuated by a bell crank lever 43 which is pivoted at 44, and

ever, a vacuum is developed within the intakev manifold 22, this causing evacuation of the cylinder 48, which results in piston 41 mov ing to the left againstthe action .of spring 50, thereby causing lengagement of the clutch. The automatic clutching mechanism just described therefore acts to disengage the clutch when the en- Agine has stopped and lto automatically engage the clutch after starting of the engine.

In accordance with the preferred form of my invention, I provide for automatically starting and stopping the engine in accordance with the temperature of the conditioned space. For this purpose a temperature controller generally indicated as l is provided, This temperature controller isl shown herein as comprising a bellows 52 which is iixedly supported at its lower end and which cooperates with a pivoted switch carrier 53 which carries a mercury switch 54. -A tension spring II is connected to theI free end of the switch carrier 52 and urges such carrier against the bellows 52. The bellows I2 contains a suitable volatile iluid wherefore the vapor pressure therein varies with the temperature surroundingthe bellows 52. Thus. upon an increase in temperature, the vapor pressure within the bellows will increase, this causing expansion of the bellows against the action of the spring Si and lu tilting the mercury switch towards 4closed position. Upon a decrease in temperature, however, .the vapor preure within the bellows will decrease, this causing contraction of the bellows under the action of the spring 55, thereby tilting l5 the mercury switch i4 .towards open position.

Reference character Si indicates a storage battery. -One terminal of this battery is grounded as at il, and the other terminal of said battery is connected to one terminal of mercury switch 54 by means of wires 58 and $9. The

other terminal of mercury switch 54 is connected toawire ,andthiswirelisconnectedtoan.

ignition coil Il and also to the control terminal of starting relay i2. The starting relay 62 may be of the type shown and described in the Loehr for this purpose is connected to the battery it and to the starting motor 2 5 by means of wires 63 and 04 respectively. This starting relayis also. arranged to prevent energization of the `starting motor so long as the engine is in op eration, as evidencedl by operation of the generator, and for this purpose is lconnected to .the generator 2l by means of wires 65 and 8 6. Reierence character 81 indicates a suitable generator cut-out for preventing discharge `of the battery 58 through the generator when said generator is not in operation.

From the description thus far, it should be apparentl that whenever the space temperature is below a predetermined value, the mercury switch 54 will be open, thereby deenergizing the start- -ing relay t2 and the ignition coil 61, this causing the engine to be stopped at which time the autol matic clutching mechanism will cause disengagement of the clutch. When, however, the space temperature rises above the value for which the' controller 5I is set, the mercury switch y54 will close, thus energizing the ignition circuit for the engine and also energizing the control circuit of the starting relay, this causing operation of the starting 'motor for starting the engine.

After the engine is started, the starting motor is automatically placed out of operation by said starting relay, and also the resulting vacuum in the intake manifold causes operation of the 6o automatic clutching mechanism for engaging the clutch, thereby causing the engine to drive the compressor, the fan, the generator, andthe circulating pump. 1

My invention also contemplates the modulat- 65 ing of the engine speed in accordance with the Jable throttle valve 1| is provided in the fuel line 12 to the intake manifold.' This throttle valve is shown herein as being positioned by a pneumatically controlled reversible motor generally indicated as 1 5, this motor beingconpressure open position. When the suction pressure to a `predetermined maximum the-valve '93 will be moved to a position wherein fes-port Il unobstructed, this causing a `maximum now of air through such port, thus Referring to the dehumidifying arrangement, it will be' understood that a suitable hygroscopic solution, such as an aqueous solution of lithium chloride, is sprayed over the air, this solution absorbing water vapor from the air, thereby dehumidifying the air. vIn order to 'obtain'continuous dehumidication move the absorbed moisture ,from the dehumidifying solution. This moisture is removed by heating the solution above the boiling point of water, thereby boiling off the water from the solution. In accordancewithmy invention, the waste heat from the engine is utilized for heating the solution, and for this purpose a jacket water heat exchanger and an exhaust gas heat exchanger ||2 are provided.. For normal conditions, the jacket heat and the exhaust gas heat from the engine will be sumcient for reactivating or drying the dehumidifying solution. At times, however, this waste heat from the gas engine essary reactivation and for this reason I provide a heat exchanger H3 which is heated by means of a gasY burner HI, this heat exchanger being placed in operation only when the waste heat from theengine is insumcient for performing the required reactivation.

Leading from the sump 8 of the conditioning chamber is a conduit H5, this conduit conveying the dehumidifying solution-from said sump to the inlet of the jacket heat exchanger III. The outlet of the jacket yheat exchanger is connected by' a conduit "IIS to the inlet of the auxiliary heat exchanger H3, the outlet of said latter heat exchanger being connected by a conduit ||1 to the inlet of the exhaust gas heat exchanger II2. The outlet of the exhaust gas heat exchanger ||2 is connected Yby a conduit H3 to the inlet of pump 38, the outlet of this pump discharging into a cooler IIS which is connectedbyconduit |20 to the'spray pipe By this arrangement, the deconcentrated solution is passed rst into the jacket heat exchanger where it is preheated, and then into the heat exchangers |I3 and II2 wherein it is further heated for driving off the moisture therefrom. The heated `and concentrated solution is then passed through the cooler and then sprayed over the air for dehumi said air. While I have illustrated the solution as being passed serially through the heat exchangers, it will be understood that if desired the solution may be passed in parallel therethrough or even these exchangers may be combined intoasingle heat exchanger. In systems of this type,it has-been found unnecessary to pass 71| it is necessary to re will be insumcient for providing the necl4 aas-gou v 4Valli, III-analitici bellows 33, thus causing expanlall of the solution through the concentrating l sion of the bellows 8 3 farther. which in turn means, and therefore a by-pass for the deconresul in the valve Il being moved further tocentrated solution arolmd the heat exchangers is provided, this by-pass being shown. herein as comprising a conduit |2| leading from tlie smnp 8 to the conduit III, this by-pass conduit being provided with aivalve |22. By adjusting valve and the valve |23 which is located in conduit IIS, the desired proportions of the solution may be passed through the concentrating means and by-passed therearound. In practice, .it has been found suiiicient to passonly 10% of the solution through the concentrating meansy and 'to by-pass 90% of the solution therearound.

The water jacket outlet ofthe engine 2l is connected by a pipe |2I to the inlet of a threeway valve 125, and one outlet of this three-way valve is connected to the heating coil within heat exchanger |I I by means of a pipe |26. The outlet of this heating coil is connected by a pipe |21 to the inlet of a circulating pump 4|23 which iugsaidgasesora by Pipe |29.

in turn is connected to the water jacket inlet vThe pump |23 may be driven by means and is shown herein as being the internal combustion engine 23. With the three-way valve |23 in the position shown, it will be apparent that when the engine is in operation, the pumpv |23 will cause a circulation of cooling water between the engine water jacket and the heat exchanger .|II, thereby transferring the jacket heat of the engineto the dehumidifying'solution which is being concen, trated. When the three-way valve is shifted to its other position,

any suitable driven by ing value.

'I'he exhaust gas heat exchanger |I2 is connected to the exhaust manifold 2| of the internal combustion engine by means of a conduit |32, a

three-way valve |33 being interposed in said conduit for causing flow of exhaust 'gases through the heat exchanger |2 or for by-passportion thereof around said heat exchanger. Y

In order to prevent the dehumidifying means from removingmore water vapor from the air than necessary to maintain proper humidity conditions within the conditioned space, a humidity controller |35 is provided, this humidity controller being shown as located within the conditioned space and being arranged to control the three-way valves |25 and |33 to thereby vary the amount of heat supplied for 'drying the solution relative humidity. 'Ihe humidity controller |35 may be of any suitable form, and is shown herein f as comprising a bell-crank lever pivoted at |36,

this lever having an actuating arm |31and a control arm |38 which in effect is' a. valve mem- 4humidity responsive device which is shown herein as comprising a plurality of strands I oi' or other moisture responsive material, these strands being secured at their upper and lower this it will be apparent that flow of jacket' water to the heat exchanger III will in accordance with variations in space 'actuated by meansv of a clamping member is connected to the actuating arm |31 while the lower clamping member is nxedly secured. Aspring |4| may be provided for urging the actuating arm |31 upwardly, for maintaining the Strands |40 taut. Upon an increase in relative humidity, thestrands |40 will increase in length, this causing' movement of the valve |38 towards the port |39. Upon a decrease in relative humidity, the opposite action will take place, namely, the strands |40 will shrink, this vcausing movement of the valve member 38 vaway from valve port |39.

The three-way'valve |25 is controlled by means of a pneumatic motor |42. This pneumatic motor may be of known form and is shown as com- If 'the hygroscopic-solution should become too concentrated, thev solution will become supersaturated with salts whenreduced in temperature by the cooler H9, this causing precipitation of salts whioh'results inclogging ofthe sprays' and deposits .on'the cooler surfaces and pipes. l To avoid these objectionable results, it is desirable to lprovide a limit controller for preventing the solution from' becoming overconcentrated. Such a controller is illustrated at |52. This controller may comprise a casing |53 `which is conprising a bellows |43 secured to a pivoted lever arm |44, this lever arm being suitably attached to the actuating arm |45 of the three-way valve. A tension spring |46 is attached to the lever arm |44 and urges said lever arm in a direction for biasing the bellows |46 towards expanded postion. thereby biasing the three-way valve lin a direction for cutting off the ilow of jacket water to the heat exchanger The three- Way valve |33 which controls the ow ofexhaust gases to the heat exchanger ||2 may be controlled by a motor |41 which is identical tojthe nected to the conduit ||5 by inlet .andoutlet pipes |54 and |55. A iioat valve |54a is located within the casing |52 and is arranged to con-V trol the now of solution through the inlet pipe |54 inI a manner to maintain a constant level of the solution within -the casing. Reference character |56 indicates a iioat, this oat being secured to the actuating arm of a bell-crank lever |51 which has 'a control arm |58 which actuates a control valve member |59 cooperating with a" valve port |50. The port |60 is connectedby an pneumatic motor |42. The bellows of these two pneumatic motors are `connected.together by air lines |48 and |49, and the air line )49 is shown in turn connected to the tank |05. The airline |49 is also connected to an air line |5| whichleads to the port |39 of the `humidity controller |35. l

When'A the space relative humidityA is excessive,

' as'being connected to a restrictor |50 which is the strands of the humidity controller will be expanded sufliciently topermit the valve member |38 to close the port |39. This will prevent entrance of air' through said port and consequently air will flow fromthe bellows of the two pneumatic motorsand the air lines |48, 49 and |5| into the low pressure tank |05-, vand the pressure Within the bellows of motors |42 and |41 will beequal to the. pressure existing in tank |05.w 'I'his will'causev maximum'contraction of pneumatic motors |42 and |41, which'in turnboth bellows as lshown, which results in the two .y three-way valves being 'so positioned that all of be decreased.' The control arrangement just described, therefore,l acts to vary the dehumidifying v -eiectiveness of vthe dehumidifying solution as the spacerelative humidity varies. It `will be apparent that if the relative humidity falls to such avalue asto completely open the port |39,

air will ow into said port at such a rate with' respectto air 'flow through the restriction |50,-

that a pressure is built up within the two pneumatic motors which will cause the three-way valves to be positioned so as to stop all iiow of airline |5| to the air line |5|. The density of the hygroscopic solution increases with the concentration thereof, and hence'the float |56 will raise and lower in accordance with changes in concentration of the solution. When the concentration is below an objectionable" value, the

float |50 willA sinksuicientl-y to pemit Valve member |59 to completely close the valve port |60, thereby preventing entrance of air through this port into the air line I.5| and the pneumatic motors` |42 and '|41. If, however, the concentrations of the solution becomes excessive,

the float |56 "will rise suiiiciently'to cause the' valve memberf|59 'to be shifted away'from port |60, this admitting airy intotlie control system which resultsl in a rise in pressure within the causes positioning of the three-way valves for reducing the' amount of heat supplied for concentating the 'hygroscopic solution. It will be apparent tha'twhen the concentration of the solution reaches'a maximum'value, the port |60 will be wide open, thereby causing the threeway valves |42 and |41 to be positioned so as to prevent owof exhaust gases and jacket water to the heatf'exchangers, thus preventing any further concentration yof the solution. When the concentration` of the solution is unobjectionable, the controller`|52-will leave the humidity controller |35- in -full control of the .heat'supplied for concentrating the solution. When the concentration becomes too'high, however,l the three-- way valves will' belmoved for reducing the -h'eat supplied fo concentrating the solution,- irrespective of the humidity controller |35. While I have shownthelcontroller |52 as being of the graduating type', it will be understood that if desired?. positive/ortwo-position type ofcontroller may `be'employed.

For most `conditions o'f operation; the-waste heat from the-internalcombustion engine will be sufficient for concentrating thehygroscopic solu tion. However, atytimes the heatv available from the engine mayfbe insuiiicient. *duev to the dehumidifying' load' being abnormal, or due to the heat to the heat exchangers and ||2, thus placing the dehumidifying apparatus out of yop eration.

use 9i considerable outside air. One feature of myinvention is the provision of .automatic control means v'for placing the burner |4 into operation whenever' the heat available fromr the engine is insunicient for concentrating the dehumidifying solutionlfPreferably thegas burner ||4 is placedinto;l operation only' when the space relative humidity,ise xfzeessivecL end when at this 6 A f x um the solucion n wo ummm n the space relative humidity is not excessive the burnershouldnotbeallowedtooperateasitis undesirable to utilize heat from an outside sourcev so long as the relative humidity is not excessive. Also. the burner should not operate whenever the solution is sumciently concentrated to secure an adequate amount of dehumldiilcation.

For controlling the ilow of gas to a A gas valve |55 is provided. This valve, if desired, may beoi the type shown and described in Patent No. 1,107,549 issued to G. A. Robertshaw on August 18, 1914. This type of valve is provided with a diaphragm for actuating the valve memberandisarrangedsothatthevalvesnapsirom opento closed positions. Due toilieutilizing oi'.4

engine vacuum as the controlling medium, itis` desirable to employ a spring I i'or'urging the valve towards closed position so that when atmospheric pressure exists above the dia thevalvewillbeheldclosedbythisspring.

The gas valve l is'shown as being controlled by a humidity controller i", this controller beingidenticaltothecontmllerlllandhavinga.

valve member I and a valve portV III. This humidity controller' |61 may be adjusted so that the valve member I does not close the bleed port VIII until the relative hmnidity rises above the point at which the port '|39 of the humidity controller III is closed. In'other words, the port I of the humidity controller I" does not close until the relative humidity rises toa value above the control'range oi the-humiditycontroller III.

-Thegasvalve Itimayalsobecontrolledby meansotavalvemember III whichisoperated by the density limit controller Illythis valve- |10 wlth'a valve port Ill. Thecontroller Illissoarrangedthat aslongas the concenh'aon of the hygroscopc solution is vabove a predetermined value, the valve member Ill will be held away -iromport ITI. When. however, the solution becomes too dcconeentratcd to secure elfective dehumidiilcation, the iloat III will lower, thus permitting the valve member III vso aman

that if desired a single controller having two sets bfvalv andportsmaybeutilizedinstead.

ofwre 1 When the space-temperaturen below a prede- A termined value, the temperature controller 5l will causethe engine-'2l to be stopped, thereby placing the entire system out oi operation. When the space temperature becomes excessive, howeve'r, the controller il. will cause starting of theengine Ilandaitersaidensiheisstarteithe automatic clutching will engage, thereby causingrtbe engineV to drive thecomu ataspeediustsuiilcientto both the coolingandthe ner to decrease the engine speed.

Vforms part of a direct expansion refrigeration system rising. In response to this -rise in suction pressure, the controller 16 causes opening of the throttle valve for increasing the engine speed to carry the increased cooling load. Similarly,

upon decreasing space temperature, less refriger-v ant will be evaporated within the cooling coil, Winch causes a reduction in suction pressure, this in turn causing the engine speed to be decreased. Due `to the transferring of the latent heat of evaporation o f the condensed water vapor to the air passingacross the cooling coil, the suction pressure controller will also respond to variations in the dehumidifying load. Thus, if the relative humidity should increase, a greater amount of dehumidification will be done, this causing the temperature of the air leaving the 'dehumidier to be further increased, and this increase in-temperature will cause increase in operationA of the engine in the manner just described. Conversely, as the relative humidity decreases, a less amount of dehumidication will be done, this causing less latent heat of-evaporation to be transferred to the air, .thereby causing areduction in temperature of the air leaving the dehumidier, which reduction in temperature will alfect the suction pressure controller in a man- Under normal operating conditions, tive humidity will not be excessive and the solu- I tion will not be too deconcentrated. 'I'hus normally the gas valve |65 will be held closed, there- Vby preventing the consumption of gas for concentrating the solution. When, however, the de humidifying load becomes so heavy that the waste heat from the engine cannot maintain proper concentration of lthe solution for mainthe rela- Vsuits', in the suction pressure of the refrigeration taining proper humidity conditions, the controllers |61 and`|52 will cause opening of'the gas valve and the supplying of heat from an outside source for securing the proper concentration of the solution. A

It should be noted that with the system which I have disclosed, `the supply of waste heat from the gas engine will be increased whenever the dehumidifying load increases. Thus, when the relative humidity increases, a greater amount of dehumidii-lcation will be done, this resulting in transferring more latent heat of evaporation to the air as it is dried, thus causing the temperature of the air passing over the cooling coil to increase. This increase in temperature will, in the manner previously described, increase the speed of the engine tocarry this increased refrigeration load. This increase in speed of ,the engine Ywill cause a greater amount of waste he'at to be ejected from said engine. Hence, as the dehumidifying load increases, a greateramount of waste heat is available from the engine for reactivating the dehumidifying solution.

' Figure 2 In Figure 2 I have shown my invention applied to a system employing a silica-gel type of dehumidifying unit. In this figure, reference character 200 indicates areturn duct leading from relay 62.

system identical with that illustrated in Figure 1, the compressor being drivenby internal combustion engine 20 in exactly the same manner as shown' in Figure 1. These details are therefore not described here. 4

'Ihe internal combustion engine 20 is stopped and started in accordance with space temperature as in Figure 1 and for this purpose I have shown a return duct type of controller 2|0 for controlling the control circuit of the starting position. When the temperature reaches a predetermined value, the mercury switch 2|5 will be closed, this causing starting of the engine in the manner described in Figure l. When the space temperature fallsto a predetermined value, however, the mercury switch 2|5 will be opened, thereby causing stopping of the engine 20.

As in the case of Figure 1, the engine 20 is provided with a throttle valve Afor controlling the fuel supply to the engine. In this case, however, the throttle valve is controlled by an engine speed governor 2|`| which is indicated as being driven by'the generator shaft. This engine speed governor is provided with acontrol arm 2|0 which is connectedto the control arm 1 |a of the throttle valve 1| by means of a spring or strain release. connection 2|9. The control arm 1|a is also actuated by means of a, pneutheconditioned space 20|, this return duct leading to the inlet -of the silica-gel dehumidifying `unit 202. The outlet of the dehumidifying unit 202 is connected to a duct ,203 leading to a conditioning chamber 204 inwhich is located a cooling coil 205. The outlet of the conditioning chamber 204 is connectedto a 'fan 206 which is f in turn connected by suitable duct means to the yconditioned -space 20|. The

matic control device 220, this controldevice comprising a bellows 22| which is linked to a lever 222, this lever being connected by a link 223 to the control arm lla. The lever 222 is pivoted at 224 and is connected toa tension spring 225 which biases the bellows 22| towards contracted position. .From this arrangement, it will be ap-v f parent that the throttle valve will assume a position in which the springs 2|9, 225 and the action of the bellows are in equiubrium. Thus for a constant pressure in the bellows 22|, the-governor 2|'l will change thetension of spring 2|9 in a mannerto position the throttle valve for maintaining the engine speed constant. If the engine` speedA should increase, the spring ten-- sion ywill be changed to permit the throttle valve to be closed, and if the` engine speed Ashould vdecrease the governor will change the tension of spring 2|9 to cause the throttle valve to move to a further open position. v'Should the pressure within the bellows 22| b'e increased, said bellows will further oppose the action ofzthe, spring 225- thereby causing the throttle valve to be moved to another position at ,which these three forces are in equilibrium. In this case the throttle valve upon an increase in pressure within the bellows 22|, will be moved towards open position. Similarly, if the pressure within bellows 22| should decrease, the throttle valve will be causedv to rnovel .l towards closed position. Variations in pressure within the bellows 22| therefore act in eiect to cooling coil 205 7.5

adjust the governor 2|1to vary the engine maintained by said governor.'

As inthe case of Figure 1, the speed of the This controller comprises a bellows 2| l speed v to bund up within the beuows 22|, this bottom troughs 254 ner to maintain the refrigeration system suction pressure constant. For this purpose I provide a suction pressure controller 226. This controller may comprise a bellows 221 which is connected to the suction line I1 by means of tube 228, said bellows being arranged to actuate a bell crankmember 229 having an actuating arm 236 and a. control arm 23| which in effect is a valve lmember cooperating with the port 232. Upon an increase in suction pressure the bellows 221 will expand against the action of a spring 233, thereby causing valve member 23| to be moved towards the bleed port 232. Upon a decrease in suction pressure the opposite action will take place, namely, 'the vbellows 221 will contract thereby' causing valve member 23| to move away from bleed port 232.

Instead of utilizing the engine vacuum as an actuating medium for the controllers, as in Figure 1, I here illustrate an air compressor 235 which is driven by the engine by means ofI pulleys 236 andl 231 which cooperate with abelt 238. The compressor'235 discharges into a tank 23S-and this tank is connected by an outlet pipe 240 to an oil eliminator 24| which in turn is connected to a pressure reducing valve 242. To the outlet of the reducing valve 242 isconnected an air supply main 243 and to this supply main is connected a restrictor 244 taking the form of a needle valve. 'I'he outlet of this restrictor is connected to the bellows 22| by a conduit 245- and to the bleed port 232 by a conduit 246. The

'restrictor 244 is adjusted to kpass a smaller amount of airthan the bleed port 232 is capable of bleeding. y

, When the suction pressure of the refrigeration system is above a predetermined value, the valve member 23| will close the bleed port 232, this allowing the full pressure of the air supply main resulting in the engine governor being adjusted to maintain a maximumrengine speed. As the suction pressure decreases, the valve member 23| will be shifted to allow bleeding of air from port 232, this causing a reduction in pressure within bellows 22| which in turn adjusts the engine governor to maintain a slower engine speed.- If the suction pressure falls to a predetermined low 4value, the valve member 23| of controller 226 unobstructed, thereby will leave bleed port 232 causing a minimum pressure to exist within the bellows 22| for adjusting the engine speed governor to maintain a4 minimum engine speed.

' The' control arrangement just described, therefore, acts to modulate the engine speed in accordance with the suction tion system. Referring nowto the silica-gel drier 262, this consists of an outer casing 250 havi ng located thereina partition 25| which divides said casing into` passages 2 52 and` 253. leach of the passages 252 and 253 are screenedadapted to contain a dehumidifying substance such as silica-gel, these troughs being partially superimposed the other and having bailles 255 therebetween for preventing flow of air between the troughs. The silica-gel adsorbs water vapor from the air and-it is necessary. to remove this 'adsorbed water periodically in order that the material will continue with its dehumidii'ying action. Ascontinuous dehumidiication is desired and as the dehumidifying Substance 'can operate only intermittently, `the two separate'dehumidifying pas- Located within One upon 9,264,914 e. engine when in operation is'controlled in a mansages are provided, one passage being arranged for dehumidifyinggwhile the material in the other passage is being reactivated.. The reactivation of the material is accomplished in this typef'of,l I dehumidiiier by passing a blast of hot air through the dehumidifying substance and for this purpose" an air heating duct 256 is provided, this' duct having located therein a jacket water' heat exchanger 251, an exhaust gas heat excha'n'gerZSil,4 and a gas heated air heating device 258. The

air heating duct 256 receives air from outside the shown, the heated air from the heat exchanger will be delivered td the passage 252. f

A t the lower end of the casing 250 isan air outlet passage 264, this passage leading from the lower central part of casing 250 to a fan 265 winch discharges the reactivating air outside of the space being conditioned. The outlet duct 264 is provided with dampers 266 and 261 which are connected together 'with a link 268 so as to move in unison. When these dampers are in the position shown, the heated air which isdelivered to the passage 252 is withdrawn through the duct 264 and discharged into outside air. With the dampers 26|, 262, 266 and 261 in the position shown, therefore, heated air from the heat .exchanger is .'passed downwardly through the passage 252 forv reactivating the gel vin communication with the ducts 200 and 203.

air thus owing from the conditionedspace around the passage 2-64 through the gel beds in the passage 253 to the duct 203 fromwhich it passes over the cooling coil back to the 'space to be conditioned. When the dampers 26|, 262,

` 266 and 261 are shifted to the dotted line posipressure4 of the refrigerations it will be apparent that the reactivating air will be passed through the passage 253 and the airto be conditioned will be passed through the passage 252.. f

The dampers 26|, 262, 266 and 261 are shifted from one position to the other by means of a fluid actuated motor 269. This motor/ is of usual form, comprising a bellows 21|) arranged for actuating a lever arm 21| which is pivoted at 212. A spring 213 is connected to the lever arm 21 and biases said lever arm against the bellows 210. The lever arm 21| is connected to a link 214 which is suitably connected to both sets of dampers so as to operate said dampers all in'unison. When the bellows 216 is contracted as shown, the dampers assume the position shown in which .the air to be conditioned is passed through passage 253 while the reactivating air is passed through passage 252. When ,the bellows 210 is expanded, however, the dempers will be shifted to the dotted line positions.

Any s itable means may be provided for periodically shifting the dampers from one position to the other, and for4 illustrateda clock 215 which is connected to a shaft 216 carrying a cam 211. The shaft 216 may be driven by the clock at av rate to cause 'one completel rotation every 20 minutes. The cam 211 is divided equally into a raised portion and a recessed portion, and cooperates with a cam this purpose I have their dotted line positions.

follower 218 which carries a valve member 218 cooperating with a' bleed port ,289. The bleed port 289 is connected by a pipe 28| to the bellows 219 and by a pipe 282 to the outlet of a restrictor 283 which in turn is connected in the air supply line 243. By the arrangement just described, it .will be apparent that when the raised portion* of the cam engages the cam follower 218 thevalve member 219 will be moved away from the port 289, thereby permitting conatracticn`of`g bellows 219 this causing the dampers to 'assumel theposition shown. When the cam 211'is rotated so that the recessed por-v tionengages the cam follower, the valve member 219 will engage the bleed port 289 thereby causing the full air supply pressure to build up within the bellows 219, this causing expansion of the bellows 219 for Yshiftig"the dampers to .just described, therefore, periodically shifts the dampers from one position to the other and in tliiies case will shift the dempers every'10 minu s. 1 Referring again to the air heating means, the heat exchanger 2,51. is connected to the outlet of the engine water jacket by means of a conduit 285. 'Ihe outlet of the heat exchanger 251 is connected by a conduit 286 to the inlet of a pump 281 which is driven by the internal combustion engine 29, this pump in turn being connected to the water jacket inlet. By this ar- The arrangement f rangement, when the engine is in operation, the

jacket water is passed through the heat exchanger 251, this providing for cooling the en gine and for preheating theV air which is beingV passed lto the dehumidifier/292 .cr/reactivating changer 258 is connected by an exhaust pipe 288 to the exhaust manifold 2| of the internal combustion engine 29. The exhaust gases for the `engine are therefore continuously passed through the heat exchanger 258. This heat exchanger and the heat exchanger 251 are preferably heavily built so as to act as heat reservoirs. The purpose of this heavy construction will appear presently. The gas heated heat exchanger 259 is provided with a gas burner 299, the supply of gas to this burner being controlled by means of a valve 29| Ywhich may be of the diaphragm type and which is so arranged as to remain closed except at times when air pressure exists under the diaphragm thereof.

Inasmuch as 'during the period of reactivation,/

the silica-gel beds are, highly heated for/driving the water therefrom, it is necessary to cool such beds before the aiuto/fe conditioned is Yriveted ge1 bed before val, the dampers will be ner that when the bellows 294 of the motor is expanded, as shown, the damper 292 will be positioned for causing the air to flow through the bypass passage 29|. When the bellows 294 is con.- tracted due to venting thereof, the motor 293 will position the damper 292 so as to close off the by-pass and cause flow of air through the heat exchanger. The bellows 294 is connected by air lines 295 and 296 to a restrictor 291, which in turn is connected to the main air supply from the tank 239. The bellows .294 is also connected by the lines 295 and 298 to a bleed port 299.

The bleed port 299 cooperates with a valve member 309, which is shown as forming a part of a cam follower 39| which cooperates with a cam 392 mounted upon the shaft 216. The cam 392 is provided with a pair of raised portions, the centers of these raised portions being spaced 180 apart and the .raised portions occupying 4portions of the cam surface corresponding to approximately 3 minutes of rotation. This cam is positioned upon the shaft 216 so that the raised portions thereof will engage the cam follower just 3 .minutes in advance of the time that the cam follower 218 rides from one portion of cam 211 to the other. Therefore, 3 minutes ahead of the time that the cam' 211 will cause shifting of the dampers, the cam follower 39| will be engaged by a raised portion of cam 392, this causing the valve member 399 to engage the, bleed port 299, which results in expansion of the bellows 294 for stopping the flow of reactivating air through the heat exchangers and by-passing such air.YYY

therearound. This larrangement,LV therefore, allows..fa..3 minute'cooling interval for the reacit is placed into service. It will be apparent that after this 3 minute intershifted and the damper 292 will again be positioned to permit flow pf reactivating air through the. heaters to cause heating of the air for reactivating the other gel passed therethr/oug-hf/For this purpose, provision is made for/stopping the heating of the reac- A ,tivating air a predetermined period of time bet fore the shifting of the dampers, thereby -permitting cool air to be blown through the bed which has just been reactivated. for cooling such bed before the air to be conditioned is passed therethrough. Preferably, this result is achieved by the use of a by-pass duct 29| which permits the reactivating air to be by-passed around the heaters 251, 258 and 259 instead of passing therethrough. For selectively passing the air either through the heaters or through the by-pass, is

provided a damper 292, this damper being arranged to either close the v`heating passage orthe by-pass passage. this damper, is provided a fluid actuated motor 293 which may be of known form, this motor being connected to the damper 292 in such man- For automatically controlling /wni/cn wiu be imparted water for beds. 1

It should be noted that the exhaust gases are continuously passed through the heat exchanger 258, and the jacket water is continuously passed through the heat exchanger 251. By making these heat exchangers of heavy construction, these exchangers will act the period of time that the gamme-T292 is preventing ow of when the damper/292 is in this position, the heat exchan ers 251 and 258 will act to store up heat to the air when the to permit flow of air damper 292 is shifted By this arrange.-

through 4said heat exchangers.

`ment, all of the -waste heatl from the internal combustion engine is utilized for reactivating the gel beds, and wasting of this heat during the cooling period for the reactivated gel bed is avoided. ,It should benoted that the cooling through heater 251, even when damper 292 is in to absorb heat/during airgtherethrough. Therefore,

the engine is continuously passed' .position for preventing air flow through the ,passed through this radiator when heater 'out of operation. Also, if desired, a suitable tank I heater. This will usually be a/satisfactory arrangement, for the volume of water in the heater and pipes 285 and 286 will absorb the engine heat for the short period while damper 292 prevents air flow through the `heater 251, without causing overheating of the engine. It will be understood that if desired, a radiator as shown at |39 in Figure l may be provided, the water being 251 is may be provided for increasing the volume of Water in the circulation system so as to provide face corresponding to cycle. When valve for accumulation of jacket heat and for properly cooling the engine While heater 251 is out of operation.

In accordance with my invention, the auxiliary heater 259 isplaced into operation whenever the Waste heat from the engine is insufficient to properly reactivate the silica-gel beds. Whenever the Waste heat is suilcie'nt for proper reactivation, however, the auxiliary 'heater -259 is to-be kept out of operation. My preferred method for controlling this auxiliaryheater is by opening the gas valve whenever the 4rate in rise of temperature of the reactivating air leaving the gelbed Vis too low. It will be understood that at the beginning of the,eaQtivatingTcycle-the gel bed which has just been taken out of service for reactivation, is relatively cool. When the heated air is passed through such bed the air issuing from the bed will be cooled. Asthe reactivation period progresses; however, the gel bed will become more and more heated, this resulting in the temperature of the air issuing from said bed increasing. If the reactivating air is sufliciently heated for securing properreactivation, the temperature of said reactivating air as it leaves the gel bed will rise morequickly than if the temperature of the issuing air is too low for proper reactivation. The rateof nse in temperatui'e of the reactivating air leaving the gel bed is therefore an indication of whether or not the heat supplied to the air is suicient. -I therefore control the gas valve 29| by a means responsive to the rate of rise in temperature of theA outgoing reactivating air. This means may consist of a reverse acting type of pneumatic thermostat 3|0 and a timing arrangement 3|| which may be driven by the shaft 216. The thermostat .3| is shown as connected to a restrictor 3|2 the heater 259 is always out of operation when by means of an air line 3 I3, the restrictor being Y connected by a line compressed air. by a. line 3|5 tofthe diaphragm valve 29| and is also vconnected to a bleed port 3|6 of the timing device 3|| by aline 3|1. arranged so that its bleed port remains closed until the temperature of the reactivating air rises to 240 F., at which time the bleed port Will be opened.

Referring now to the timing device 3H, this comprises a cam 3| 8 3M to themain source of 3|9 .which carries a valve member 320 cooperating with the bleed port 3|6. This cam is provided with a pair vof raised portions and a pair of depressed portions, the centers of'A the raised portions being spaced 180 apart and the raised portions each occupying a portion of the cam sur- 6 minutes of rotation of shaft 216. 'Ihis cam is molmted upon the shaft 216 in such a manner that one raised portion engages the follower 3|9 just 3 minutes ahead of the time that the cam follower 218 rides'from one portion of cam 211 to the other. In other words, the cam 3|8 is so mounted as to cause opening of the bleed port 3|6 just 3 minutesbeforev the end of a reactivating cycle. Due to the raised portion of the cam` surface occupying a 6 minutes interval, the valve 32|I will be held away from bleed port 3|9 for the last 3 minutes of one cycle and for the rst 3. minutes of the following 320 is held` away from port 3|6, air will bleed from said port, this causing a reduction in air pressure under the diaphragm of the gas valve 29 thereby causing said valve to be closed. vThis arrangement therefore acts t0 main- The air line 3|3 is connected The thermostat 3 IlA is which is driven by the shaft 216 and which cooperates with a cam follower system of Figure 1.

value, for instance 75,

.bed 'which has just ever the reactivated air is the heaters.

At the beginning of a reactivating cycle, the dampers 26|, zsz, 26s and 261 win be shifted to cause the air being conditioned to flow through Vthe gel bed which has just been reactivated, and

to causeeflowgof the reactivating air through the gel bed just taken out of service. At this time, the damper 292 will be shifted to cause the reactivating air to pass through the heaters," thereby causing heated airto flow through the bed being reactivated'. For the rst 3 minutes of this reactivating cycle, the valve 29| will b prevented from opening, due to the cam- 3|8 causing opening of the bleed port 3|6. During this time, the temperature of the reactivating air leaving the gel bed will gradually increase, and when the temperature increases to 240 the bleed port of the duct thermostat 3| 0 wll open. If this condition occurs, the diaphragm chamber of the gas valve will continue to be vented even after the 3 minute interval, when the cam 3|8 causes closing of the bleed port 3| 6. This arrangement, therefore, acts to maintain the gas valve 29| closed if `the temperature of the discharged reactivating air rises to 240 F. within 3 minutes after the beginning of a reactivating cycle. If, however, the reactivating air temperature fails to rise'to 240 F. within this interval, both the bleed port 3|6 and the bleed port of the thermostat 3||l will be closed at the end of this interval, this causinglpressure to build up under the diaphragmof the gas valve 29| for opening said valve to place the auxiliary heater 259 into operation. This arrangement, therefore, prevents operation of the auxiliary heater 259 so long as the supply of waste heat from the engine is suiiicient for securing proper reactivation. When the waste heat is insufficient, however, the'heater 259 is automatically placed into operation.

It should be apparent from the foregoing description, that the operation of the system shown in Figure 2 is generally the same as that of the Thus, when the space or return air temperature is below a predetermined the controller 2||l will cause the engine to be stopped, thereby placing the system .out of operation. When, however, the space temperatureA rises above this value, the

`space temperature controller 2| 0 will cause starting of the engine. When the engine is in operation, the suction pressure controller 226 will modulate the engine speed in a manner to carry both the sensible heat and latent heat cooling loads, just as occurs in Figure 1.

the operation of the system, the air for reactivation will be passed through the dehumidifying chambers in alternation, thus providing for reactivating one chamber while the other chamber is in use. Also, before the end of each reactivation cycle, the heating of the reactivating air will be stopped, thereby providing for co'oling of the gel this time the auxiliary heater will be kept out of operation by the timing device 3H. Also, if the being by/-passed around been reactivated, and during' -goperatelmplacea ated device for causing movement of said speed controllenmeans actuated by said engine for providing actuating fluid for said uid actuated device, means responsive to a condition of the re- 5 frigerant evaporated in said cooling coil for conto a predetermined value. Instead of' this arrangement, a humidity controlled by-pass around the dehumidifier 202 may be provided.

It will be noted that my system permits the use of all or substantially all return'air.v By using practically all return air, the total cooling load is considerably reduced as compared to an arrangement in which all outside air is used.` By

this reduction-in load, the waste heat from the engine will be capable of supplying sufficient heat to reactivate the dehumidier under most conditions, It is of course desirable to utilize a cerro ling the actuating fluid supplied to said fluid actuating device to vary the engine speed in a manner to maintain said evaporated refrigerant condition between predetermined limits, means for utilizing heat ejected by said engine for reactvatingsaid dehumidifylng means, and means for controlling the supply of said heat to said de-l humidifying means. 3. In an air conditioning system, in combination, a dehumidifier comprising a passage, moisture collecting material in said passagehineans for alternately passing air air for reactivating-said dehumidifying material through said passage, cooling means for cooling the dehumidied air means for supplying including a cooling coil and said cooling fluid supplying means for heating said reactivating air, auxiliary heating means for tain percentage of outside air for Ventilating heating said reactivating air, by-pass means for purposes even though the total cooling load is thereby increased. When fairly large quantities of outside air are utilized, thewaste heat from the engine will not be sufficient for reactivating auxiliary heating demeans,

the dehumidifier, and the vice will come into action for providing the extra heat necessary for reactivating the dehumidifier.

From the'foregoing description, it should be '-apparent that I have provided an air conditionby-passing said first mentioned heating means,

for causing unheated air to -be passed through said dehumidifying material for cooling the same, automatic means for loperating said by-pass, and means' for preventing operation of said auxiliary heating means when said by-pass means is in operation,

4. In an air conditioning system, in combination, a dehumidifier comprising a passage, moising system which is especially adapted to bev acture Collecting material in Said passage, means tuated by'm'eans of an intemal combustion engine, this airconditioning system utilizing the Waste heat ofthe engine for also conditioning the air and being automatically controlled in a. manner to maintain proper temperature midity conditionsv While my invention is mainly concerned with air conditioning systems utilizing an internal combustion engine, certain features of my invention are of broader application. Also, while I' have shown and described novel pneumatic control arrangements, it is to be understood that certain features of my invention may vbe cohtrolled by electrical arrangements as well as pneumatic control arrangements.' Inasmuch as many modifications of my invention will be obvious to those skilled in the art, I desire to be limited only by the scope of the appended claims and the prior art.

I claim as my invention:

l. In an air conditioning system, in combination, a dehumidifying meansof the type requiring heat for reactivation, a .cooling means for the air, means for actuating said cooling meanscomprising an internal combustion engine, means for utilizing heat ejected by said internal combustion engine for reactivating said dehumidifylng means, and humidity responsive means for controlling the flow of said ejected 'heat to said de- V for reactivation, a direct expansion cooling coil in said conditioning chamber, means for actuating `said direct expansion cooling coil comprising an internal combustion engine driven compressor, a speed controller for varying-the speed oi said internal combustion engine, a fluid actuand hu- 40 ing for alternately passing air to be dehumidified or through said passage, cooling means for cooling the dehumidied air leaving said passaggi/mandy a cooling coil arid/means/i-olfsupplying said for transferring-heat ejected from said cooling fluid supplying means to said reactivating air for heating the same, by-pass means for by-passing said reactivating air around said heat exchanger to cause unheated air to be passed 'through said moisture collecting material for cooling the same, and means for controlling said by-pass means, said heat exchanger being of sufficient size to absorb and store .heat during the continuous operation of said cooling fluid supplying means While said reactivating air is being by-passed around said heat exchanger.

' 5.' In an air conditioning system, in combination, a conditioning chamber through which air tojb-e conditioned is passed, a dehumidifying means in said chamber of the type utilizing a material causing condensation of the water vapor in the air and transfer of the latent heatof evaporation of the water vapurgto,.thea/ir thereby causing the air to be,rais'd in temperature during the dehumidifying action, a refrigeration system including an evaporator in said chamber for cooling the dried and heated air, said refrigeration system includng a compressor driven by an vinternal combustion engine, means for utilizing heat ejected by the internal combustion engine for reactivating the dehumidifying material, and means responsive to a condition of the refrigerantl in said evaporator which varies upon change in load on the evaporator for varying the speed offsaid internal combustion engine.

6. In an air conditioning system, in combination, a conditioning chamber through which air to be conditioned is passed, a. dehumidifying' to be dehumidifed or said cooling coil with cool-` ing iluid, means for utilizing heat ejected from causing the air to be raised in temperature uring the dehumidifying action, a re/frige ion systern including an evapor/ator/ in said chamber for cooling the dri/ed/and heated air, said reirigeration system/including a compressor driven means in said chamberwof the type utilizing a material causing condensation of the water vapor in the air and transfer of the latent heat of evaporatio f the water vapor to the air thereby causingnlafutcewraise mperature during the dehumidifying action, a refrigeration system including an evaporator in said chamber for cooling the driedv and heated lair, said refrigeration system including a compressor driven 'by an internal combustion engine, means. for utilizing heat ejected by the internal combustion engine for reactivating the dehumidifying material, means responsive to the demand for dehumidiiication in said space for controlling the delivery 'of heat from said internal combustion engine to said dehumidifying means, and means responsive to a condition-of therefrigerant in saidy evaporator which varies upon 'change in load on the evaporator for 'varying the speed of said internal combustion engine.

8. In an air conditioning system, in combination, a conditioning chamber through` which air 'to be conditioned is passed, a dehumidifying means in said chamber of the type utilizing Vmaterial causing condensation of the water vapor in the air and transfer of the latent heat of evaporation of the water vapor to the air thereby causing the air to be raised in temperature during the dehumidifying action, a refrigeration system including an evaporator in said chamber in the air and transfer 4;, evaporation of the water Nomamg the air to be for cooling the dried and heated air, said refrigeration system including a compressor driven by' an internal combustion engine, means for utilizing heat ejected by the internal combustion engine for reactivating the dehumidifying mate- ,arngans including means for controlling th'e delivery of heat from said internal combustion engine to said and means responsive to a conditioned the redehumidifying means,

irigerant in said evaporator which varslpon change in load on the evaporator Ior-varyingvthe Vspeed of said internal combustion engine.

9. In an air conditioning system, in combination, a conditioning chamber through which to be conditioned is passed, a dehumidifying means in said chamber of the `type utilizing a material causing condensation of the water vapor -in the air and transfer of the latent heat of evaporation of the water vapor to the air thereby causing the air to be raised in temperature p during the dehumidifying action, a refrigeration system including an evaporator in said chamber ror cooling the`dried and heated air, said refrigeration system including a compressor driven by an internal combustion engine, means for utilizing heat ejected by the internal combustion en gine for reactivatingthe' dehumidifyin'gmaterial, means for controlling the delivery of heat from said internal combustion engine to said dehumidifying means, and means responsive to a. condition of the refrigerant in said' evaporator which varies upon change in load on the evaporator for air, said refrigeration system including a compressor driven by an internal combustion engine, means for utilizing heat ejected by the internal combustion engine for reactivating the 'dehumidifyingV material, mearm responsive to' a condition of the refrigerant in said evaporator which varies upon change in load on the evaporator for varying the speed ofA saidinternal combustion engine, whereby' the heat available from the internal combustion engine is limited when. the cooling load is light, auxiliary heating means'A for supplying additional heat for reactivating the dehumidifying material, and means for placing said auxiliary heating means into operation when the heat available from Asaid engine is insumcient to perform the necessary reactivation.

by an internal combustion engine, means for A1o varying the speed o1' said internal combustion utilizingrhea-t ejected by the internal combustion engine.

engine for reactivating the dehumidifying mate- 10. In an air conditioning system, in com-YY rial, means responsive to the demand for debination, a conditioning chamber through which humidifcation in said space for controlling said air to be conditioned is passed, a dehumidifying dehumidifying means, and means responsive to l5 meansin said chamber of the type utilizing a a condition of the refrigerant in said evaporator material causing condensation of the water which varies upon changevin load on the evapovapor inthe air and transfer of the latent heat rator for varying the speedof said internal comof evaporation of the water vapor to the air bustion engine. thereby causing the air to be raised in tem raif 7. In an air conditioning system, in combina- 20 .ture during the de idifyingarn-Eition, a conditioning chamber through which air frigeratign/system including an evaporator `ln to be conditioned is pas ed,a*del1pmidifyingJ-saidhamber for cooling the dried and heated 11. In an air conditioning s stemila-combina" tion, a conditiogh which air to be conditioned is passed, a dehumidifying means in said chamber of the type utilizing a material causing condensation of the water vapor of the latent heat of vapor to theair thereraised in temperature during tldehnmidii g action, ra refrigeration system including an tirsidcwel for cooling the dried and heated air, said refrigeration system including a compressor.- driven by an internal combustion engine, meansA for utilizing heat ejected by the internal combustion engine for reactivat terial, means responsive to a condition of the refrigerant in said evaporator which varies upon change in load on the evaporator for varying the speed of said internal combustion engine whereby the heat available from the internal combustion engine is limited when the cooling load is light, auxiliary heating means for supplying additional heat for reactivating the dehumidifying material, and means responsive to the mois- `ture content of the dehumidifying material for placing-said auxiliary heating means into operation when said moisture content rises to a predetermined value.

12. In an air conditioning system, in combination, a conditioning chamber through which air to be conditioned is in the air and transfer of the latent heat of evaporation of the water vapor to the air thereby causing the air to be raised in temperature during the dehumidify'ing action, a refrigeration ing the dehumidifying ma- Y bustion engine islimite'ol means in said moisture responsive means' for controlling the syste-m including an evaporator' in said (chamber for cooling the dried and heated air, said refrigeration system including va compressor driven by an internal combustion engine, means for utilizby 'the internalcombustion en- 5 vgine for reactivating the. dehumidiiying material,. j meansres'ponsive to a ing heat ejected condition of the refrigerant .insad evaporator which varies upon` change in load on .the evaporator for varying'the vspeedv of said internal combustion engine where- 10 by the heat available -from'the internal comwhen the cooling load is light; auxiliary heatingA means. for supplying additionalheat for reactivating the dehumidiying material, andtime-and temperature respon-15 sive means for .controlling said auxiliary heating means in a manner to place it .into operation when the heat from the. engine is insufficient.l

' 13. In. anair vconditioning system, in 'combinauon, a conditioning chamber through which 2'0- air to be conditioned passed; dehumidifying requiring heat'for reactivation, cooling means for cooling the dehumidifier-1 air including-'a' 25 cooling coil and means for supplying saidv coolving coil with'cooling 'heat ejected from duid, Ameans Vfor utilizing the cooling fluid supplying means for f reactivating' said dehumidifying means, auxiliary heating means f additional heat for reactivating'said dehumidifying means, means responsive to a condition of the dehumidifying ,means, means .responsive to the humidity 'of the air-.in said space, said twol responsive means conjointly oontrollng' `l said 35 "auxiliary-heating means.

-14. In 'an air conditioning system, combina-f `huinidiztiedair including a cooling coil and means for supplying .said 4cooling coil-with cooling fluid?,

means for utilizing heat ejected :from said--cool- 45 ing uid supplyingmeans for.l heating*saLidiel-f'v activating-air, auxiliary'heatingmean's for heat. ing said reactvating air, timing Vinean s,"te`m perature responsive means responsive tothetelzxzlfA perature ofthe reactiva-ting .air passing from; 50 said ,moisture collecting materlal,.. said timing means and saidl temperature responsive means "cooperating to control -said auxiliary .heating-- l5.l In an air'conditioningsStem-,in combina# 55 tion,a conditioning--chamber through which -air Y .to lie-conditioned 1s passed, dehumidifyingm'eans in said chamberfoidehumidifying said air,1said dehumidifying'nieans being of the-type'requir` ingjheat foi freact ivation, cooling meansforcool- 60 ing the dehumid-ied enf-includingl a cooling coil and means for. supplying said cooling coilzwith cooling lfluid, means for tilizing heatejected .from the being limited by the demand for cooling.' whereby at times Ithe'heat'eje'cted bye-.the cooling uid is insuicient for reactivation,

supplying.' means .heatfor motivating said.cehumiduymgnieans.jg

the relative cessive .for placlng said auxiliary heating means chamber for dehumidifying said air, said dehumidifying means being of the* type,

or. supplying 30.

. bustion eng-inc tending -conduitsof said pneumatic systems apressure cooling fluid supplying means for re- -ctivating said dehumidifying-means, the beato!! .available .from the coolingfluid supplying-ixleans dehumidifying means, means responsive to a condition of the cooling coil indicative of the de humidif'ying loadfor controlling vsaid cooling iiuid supplying means, andmeans actuated when humidity of thev air becomesex in operation.

16. In an air' conditioning system, in combination, a conditioning chamber through which air to be conditioned is passed,l dehumidifying means in. said chamber for dehumidfyingsaid air, said dehumidifying means being of the type requiring heat for' reactivation, cooling means for cooling the .'dehumidied. air f including a cooling coilland means forsupplying said cooling coil with cooling fluid,. means for utilizing heat ejected vfrom the cooling fluid supplying means for reactivating saidV dehumidifying means, the heat available from thecooling-fiuid supplying meansbeing limited by the demands for cooling,

'wherebyVv at times the heat'ejected by the cooling fluid supplying .means is insuilicient for reactiva- L tion, auxiliary heating means for supplying addifor reactivating said dehumidifying tional'heat means, and means :responsive to a condition -of' '-.thel dehumidiying meansand to the humidity in 'said space for. placing said auxiliary heating means intooperatio'n when either "condition indicates'that the dhurnidifying efectivenesso'f said dehumidifyingmeans h asabecome too low.

s 5. l'l.v In anairconditioning-system, a conditioning chamber throughwhich air to be conditioned `-is'passed,'an.evaporator' coilin heat transfer relationship with said'-l chamber, a compressor for 'supplying-refrigerant to'saidcoil, an internal combustion engil'1e for driving said compressor, aspeedcontroller for@ said engine, apneumatic control system for. said speed controller including a control valve responsivef'to a condition indicativelof the demand for compressor opera- ;tion, further conditioning 'equipmentin said duct, 'means for'utilizing waste heat 'from said engine in connection with the operation of said further conditioning" e u-pment, a pneumatic controlA system' `for sj'aid waste heat utilizing means, and means driven by said internal comto maintain within the other than atmospheric pressure.

combustion engine for driving said compressor,

'aspeedcpntroller. for said engine, a pneumatic control system for said-speed controller including'a .control valve responsive to a condition in-- dicativefof the-.demand -for Vcompressor operation,

further conditioning' equipment in said duct,

means .for utilizing waste heat fromsaid 'engine 3in1 connection withthe operation of said further conditioning equipment, a vpneur'xiatic control system .forsaid waste heat utilizing means,` land a connection between the conduitsl o f said pneumatic .systems and theintakemanifold ofsaid engine tending tol-'maintain a. vacuum within xsaidconduit. l auxiliary heating means for supplyingadditlonal 70- 

